GUI Reference
R&S
®
ZNC
168
User Manual 1173.9557.02 ─ 13
Flatness / Gain / Slope
Displays or hides trace parameters that the analyzer calculates for the selected evalua-
tion range ("Eval Range...").
Suppose that A and B denote the trace points at the beginning and at the end of the
evaluation range, respectively.
●
"Gain" is the larger of the two stimulus values of points A and B.
●
"Slope" is the difference of the stimulus values of point B minus point A.
●
"Flatness" is a measure of the deviation of the trace in the evaluation range from
linearity. The analyzer calculates the difference trace between the active trace and
the straight line between points A and B. The flatness is the difference between the
largest and the smallest response value of this difference trace.
Remote command:
Compr Point / Value
Displays or hides all results related to the x-dB compression point of the trace, where x
is the selected compression value. To obtain valid compression point results, a power
sweep must be active, and the trace format must be "dB Mag".
The x-dB compression point of an S-parameter or ratio is the stimulus signal level where
the magnitude of the measured quantity has dropped by x dB compared to its value at
small stimulus signal levels (small-signal value). As an approximation for the small-signal
value, the analyzer uses the value at the start level of the evaluation range ("Eval
Range...").
The compression point is a measure for the upper edge of the linearity range of a DUT.
It is close to the highest input signal level for which the DUT shows a linear response (|
a
n
| —> x*|a
n
|
➪
|b
n
| —> x*|b
n
|, so that the magnitude of all S-parameters remains con-
stant).
When "Compression Point" is activated, a marker labeled "Cmp" is placed to the com-
pression point with the smallest stimulus level. Moreover the movable "Trace Statistics"
info field shows the numerical results of the compression point measurement:
Trace Settings
